Swimming Pool Regs 702

[sythai]

Hi Guys

Been to look at a job, as follows :

• Existing Swimming Pool House 20meters away from main house, DB in here on TT set up, Ze = 90ohms.
• Plan is to come off here to supply another outbuilding which is about 15metres away.

Just wanting to make sure DB I'm coming off of is compliant, as I'll potentially be the last one touching it.

Looking through section 702, seen 702.410.3.4.3(ii) mentions a figure of 20ohms or less if using an electrode to backup PME - that confuses me as thought you couldn't mix the two ! Which leads on to the question of with the Ze of 90ohms, is this ok as its under 200ohms or does it have to be under 20ohms ?

Hopefully this makes sense - sorry its been one of them days.

Cheers Sy ;-)

 

[Ian1981]

If the set up at the origin is TT , then 702.410.3.4.3(ii) is irrelevant

 

[sythai]

If the set up at the origin is TT , then 702.410.3.4.3(ii) is irrelevant

Thanks Ian


PME is back at main house cut out
TT at pool house (20 metres away from main house)

 

[Wilko]

Hi - I would likely add a new set of rods to a new outbuilding and then join the two TT boards together via the SWA armour.

 

[davesparks]

Looking through section 702, seen 702.410.3.4.3(ii) mentions a figure of 20ohms or less if using an electrode to backup PME - that confuses me as thought you couldn't mix the two ! Which leads on to the question of with the Ze of 90ohms, is this ok as its under 200ohms or does it have to be under 20ohms ?

What do you mean by can't mix the two? Yes they recommend a sub 20ohm Ra if connecting an earth electrode to a PME system, that's not mixing anything though, just connecting an earth electrode.

Is 90ohms a normal value for a TT system in this area? Does it seem unusual or is it what you would expect to get from a good earth electrode setup in your area?

Are you able to determine how many rods have been used to make up the earth electrode for this TT supply?

 

[sythai]

What do you mean by can't mix the two? Yes they recommend a sub 20ohm Ra if connecting an earth electrode to a PME system, that's not mixing anything though, just connecting an earth electrode.

Is 90ohms a normal value for a TT system in this area? Does it seem unusual or is it what you would expect to get from a good earth electrode setup in your area?

Are you able to determine how many rods have been used to make up the earth electrode for this TT supply?

Cheers Dave.... 90 is normal around here.
Regards to PME and earth electrtode together, always good to check thank you for clarifying ;-)